220 E VOL UTION AND DISEASE 



the spot, and reinforce their comrades ; as a result of 

 this encounter many of the leucocytes die, others fuse 

 together and form giant-cells : the dead leucocytes form 

 pus cells and give rise to the caseous centre in the 

 nodules, whilst along its confines, in the bacilliferous 

 zone, the conflict continues to rage. The giant-cells are 

 powerful antagonists, for I have seen one contain as 

 many as fifty bacilli. From these nodules the bacilli are 

 conveyed by blood-vessels, or even carried away by the 

 leucocytes, and initiate new struggles in distant parts. 

 It must also be remembered that after their introduction 

 into the body the bacilli will, if the conditions of the host 

 be favourable, multiply very rapidly, and in due course 

 overrun the whole system ; nodules arise in the liver, 

 lungs, brain, and skin ; function is interfered with and 

 death results. In addition to the local troubles the 

 invasion of an organism by bacteria produces general 

 disturbances, one of the most important being an 

 increase of the temperature of the body, usually termed 

 fever. 



It must be borne in mind that local lesions are not 

 necessary results of the entrance of pathogenic organisms 

 into the system. In such a disease as anthrax we have 

 one local sore indicating the seat of inoculation, but 

 beyond the presence of the bacilli in the blood we have 

 no special tissue-change enabling us to identify the 

 nature of the disease, the general disturbance and fever 

 in anthrax conforming to that characteristic of acute, 

 specific, contagious maladies in general. 



The behaviour of leucocytes to pathogenic bacteria 

 constitutes the essence of the inflammatory process. It 



